Method of hulling paddy and device therefor

ABSTRACT

A method of hulling paddy which comprises revolving numerous hulling vanes having outer bent ends to produce a lower atmospheric pressure zone which is virtually the same as the vacuum state, passing paddy through the said lower pressure zone to expand the gas in paddy abruptly thereby rendering paddy to the state just before the crack and immediately thereafter throwing paddy against outer bent ends of the hulling vanes to crack the hulls and then discharging the cracked paddy into the air pressure zone so that hulls and husked rice are separated perfectly.

United States Patent Inventor Yutaka Aoki Tokyo, Japan App]. No. 743,565Filed July 9, 1968 Patented Mar. 2, 1971 Assignee Sanriku Noki Co., Ltd.Priority July 13, 1967 Japan 42-45203/67 METHOD OF HULLING PADDY ANDDEVICE THEREFOR 6 Claims, 7 Drawing Figs.

11.8. C1 146/223, 146/273 Int. Cl B02c 13/28, B02c 13/08 Field of Search146/223,

[5 6] References Cited UNITED STATES PATENTS 758,664 5/1904 Kimballl46/253X 1,735,550 11/1929 Stanley 146/253 1,788,686 l/1931 Mott 146/2532,098,521 11/1937 Seymour 146/253 3,255,793 6/1966 Clute l46/223XPrimary Examiner-Andrew R. Juhasz Assistant Examiner-Z. R. BilinskyAttorney-Oberlin, Maky, Donnelly & Renner ABSTRACT: A method of hullingpaddy which comprises revolving numerous hulling vanes having outer bentends to produce a lower atmospheric pressure zone which is virtually thesame as the vacuum state, passing paddy through the said lower pressurezone to expand the gas in paddy abruptly thereby rendering paddy to thestate just before the crack and immediately thereafter throwing paddyagainst outer bent ends of the hulling vanes to crack the hulls and thendischarging the cracked paddy into the air pressure zone so that hullsand husked rice are separated perfectly.

PATENTEUHAR 2mm 13566345 SHEEI 1 BF 3 43 I L 27 3a FIG. I a

INVENTOR PATENTEU HAR 2 I97] sum 2 BF 3 METHOD OF HULLING PADDY ANDDEVICE THEREFOR BACKGROUND OF THE INVENTION This invention relates to amethod of removing the bulls from paddy and a device for embodying suchthe method.

Heretofore, hand millers, rubber-roller hullers, collisiontype hullers,etc. have been used to remove the hulls and produce brown rice frompaddy, and more particularly, the automatic rubber roll type hullerwhich comprises separator, winnower and screen coordinated by a throwingelevator is the most popular and diffused type. The separator of therubber rolltype huller is composed of two symmetrical rubber rolls,which are placed closely together and revolve in opposite directionswith different speed ratio of rotation. Therefore, paddy, when passedbetween the rolls, is given a twisting squeeze as done by two fingersand as a result the husks are peeled off.

According to the conventional rubber roll huller, an adjust ment ofclearance between two rolls is difficult and the hulling efficiency isnot sufficient. Generally, paddy is subjected to the huller twice,nevertheless, considerable amount of unhusked paddy still remains and,further, complicatedness' in the structureof the huller requires a greatdeal of skill for operation and, therefore, causes inconvenience to thetreatment.

While, the collision-type huller is composed of a centrifugal rotor,which tosses paddy with added speed, and a separatio board, which stopsand breaksthe husks. 4

According to the conventional huller of this type, the hulling yield isrelatively low due to the incomplete dryness of paddy and to the highspeed of rotation, and further the rice cracks and the embryo drops offthus deteriorating the suitability of long preservation of rice.

After an extensive research, the inventor has traced the fact that thebulls may be perfectlyremoved from goodand even immature paddy in such away that paddy is rendered to the state just before the crack byutilizing the difference of the atmospheric pressure between the gascontained in paddy and the air, and the characteristic nature of paddywithin the air fluid, and immediately thereafter the tip of paddy isgiven an instant impact and then discharged into the strong air pressurezone, so that not only good paddy but also immature paddy is completelyhulled.

According to this method, the hulling yield is virtually perfeet withremarkable preservability of rice as compared with one obtained by theconventional huller and there is substantially no damage and crush ofrice.

SUMMARY OF THE INVENTION It is thus a principal object of the inventionto obviate all defects in the conventional roll and collision-typehulling device and to provide a new method of hulling paddy with thesubstantially perfect hulling efficiency and simple manner.

Another object of the invention is to provide a method of hulling paddywhich comprises revolving numerous hulling vanes having an outer bentend to produce a lower atmospheric pressure zone virtually the same asthe vacuum state in the vicinity of the said bent end, passing paddythrough the said lower pressure zone to expand abruptly the gas in paddythereby rendering paddy to the state just before the crack andimmediately thereafter throwing paddy against the outer bent end tocrack the hull and then discharging the cracked paddy into the airpressure zone so that the hulls and brown rice are separated perfectly.

Still another object of the invention is to provide a new method ofhulling paddy which comprises sucking paddy with a suction hose,transferring paddy into a hulling chamber, separating the air flow bymeans of a cyclone separator and selecting the resulting mixture intobrown rice, hulls, immature grains etc. by a winnower means to finallyobtain brown Even still another object of the invention is to provide anew hulling device of simple structure with a high hulling yield, whichmay be operable rapidly with ease.

And yet another object of the invention is to provide a new hullingdevice which comprises circular hulling chamber in which numeroushulling vanes are radially arranged around a rotary shaft, a cycloneseparation means for separating air now from the hulled mixture and awinnower means for selecting the hulled mixture into brown rice,immature paddy and hulls with straw dust.

And another object of the invention is to provide a paddy supplier whichcomprises a paddy suction means for sucking the piled paddyautomatically into the hulling chamber and an air suction adjuster.

A further object of the invention is to provide a circular hullingchamber in which numerous hulling vanes having an inner bent end forguiding paddy onto the center surface of the hulling vane and an outerbent end to which a tip of paddy collides are radially arranged around arotary shaft.

Yet a further object of the invention is to provide a hulling vanehaving an inner bent end for guiding paddy onto the center surface ofthe hulling vane and an outer bent end to which a tip of paddy collides.

And a further object of the invention is to provide a new hulling devicewhich may be associated with a combined harvester-thresher.

BRIEF DESCRIPTION OF THE DRAWING These and other objects and advantagesof this invention will become readily apparentand understood from theaccompanying specifications and drawings in which the same referencenumerals designate the same or similar parts throughout the drawings.

FIG. I is a perspective view of hulling device provided with a funnel;

FIG. 2 is a perspective view of hulling device provided with a suctionnozzle;

FIG. 3 is a fragmentarily enlarged front elevation of hulling chamberwhich is one of essential features of the device according to theinvention;

FIG. 4 is a plane view of hulling vane according to the invention;

FIG. Sis a side view of FIG. 4;

FIG. 6 is a pictorial view showing process for selecting paddy accordingto the invention; and

FIG. 7 is a pictorial view showing driving operation of hulling deviceaccording to the invention.

DESCRIPTION OF THE PREFERRED EMBODIMENTS In FIGS. 1 to 3, the referencenumeral 1 denotes a funnel for storing paddy, and paddy thrown into thesaid funnel l is sucked into the hulling chamber 2 together with an airflow passing through a mesh portion 3 provided at the bottom end of thefunnel 1 due to the gravity of paddy and the suction effect caused bythe revolution of numerous hulling vanes arranged in the hulling chamber2. Alternatively, one end of the suction hose 5 is connected to a paddyinlet 4 of the hulling chamber 2, while the other end thereof isprovided with a suction nozzle 6 as shown in FIG. 2. In operation, thenozzle 6 is inserted into the deposit of paddy to suck paddyautomatically into the hulling chamber 2. It will be noted that anamount of air suction through the suction nozzle 6 may be adjusted by anauxiliary air inlet means 7 which comprises several hollow pipes ofdifferent diameters and attached to the terminal por' tion of thesuction nozzle 6.

In the hulling chamber 2, numerous hulling vanes 8 are arranged radiallyaround the rotary shaft 10 and are strictly held through the weldingprojections 9 between two side plates 11 which rotate integrally withthe hulling vanes 8 around the rotary shaft 10. The side plates 11 arecontained in a circular casing 12 to which a circular covering 14 ismounted through a clamping means 13. Around an inner circumferentialwall of the circular casing 12 is detachably linedwith a circularelastic plate of rubber or plastic material through a carrier 16 toabsorb the shock of brown rice to the said inner circumferential wall.That is to say, when the elastic plate 15 is subjected to abrasion anddamaged due to the extended period of use, it may be readily substitutedfor a fresh one merely by removing the carrier 16.

As shown in FIGS. 4 and 5, the hulling vane 8 comprises a straight mainpart 17, a inner bent end 18 for guiding paddy and an outer bent end 19to which the tip of paddy collides. The inner bent end 18 and the outerbent end 19 are strengthened at the respective roots 20 and 21. Thecurvature of from 20 to of the inner bent end 18 against the main part17 of the hulling vane facilitates a smooth slide of paddy, suckedthrough the inlet 4 into the hulling chamber 2, along the surface ofvanes. While, it has been experimentally confirmed that the curvature offrom 40 to 45 of the outer bent end 19 to the main body reduces theatmospheric pressure substantially to the same as the vacuum state uponrevolution of the hulling vanes at 1,600 rpm.

Further, the outer bent portion at its inner corner 22 is somewhatprojected in an acute form as shown in FIG. 5 so as to inhibit anyleakage of collision of paddy to the said outer bent end.

The hulling vane 8 according to the invention is the most importantfeature of the present invention, so that the degrees of the curvaturesof the bent ends 18 and 19 as well as the nature of material of thehulling vane affect seriously to the hulling efficiency and also qualityof brown rice obtainable. More particularly, the outer bent end 19 ofthe hulling vane is preferably composed of the material havingelasticity sufficient enough to prevent the crush of brown rice and ahigh resistance to abrasion since the tip of paddy collides to the outerbent end of the hulling vane just in such the state that an arrowthrusts the material.

As shown in FIG. 3, the paddy entrance 4 opened at the center of thecircular covering 14 is provided with a segmental flange portion 23.along the length of the rotary shaft of the hulling varies, whichserves to inhibit an entrance of paddy into a certain direction, so thatpaddy led into the hulling chamber is never discharged directly toward apaddy outlet 24 provided at the right upper portion of the circularcasing 12 without paddy being discharged into the air pressure zonecaused between the inner circumferential wall of the casing 12 and theouter bent ends of the hulling vanes. Thus, paddy introduced into thehulling chamber through the funnel 1 or the suction hose 5, runs fromthe inner bent end 18 along the center surface of hulling vane in suchthe manner'that paddy is subjected to the most reduced air resistance,i.e. in the longitudinal form with the head of paddy. Upon revolution ofthe hulling vanes, the zone of the outer bent end of the hulling vanefalls substantially in the vacuum state and as a result, the atmosphericpressure is remarkably reduced. When paddy sliding down along thesurface of the hulling vane comes in the said lower atmospheric pressurezone, the gas contained in paddy expands abruptly and paddy is renderedto the state just before the crack. Immediately thereafter, the tip ofpaddy collides to the outer bent end 19 of the hulling vane and as aresult, the hull is split into exact halves. The thusly split paddy isfurther discharged into the air pressure zone caused between the outerterminals of the hulling vanes and the inner circumferential wall of thecircular casing, where the hulls and brown rice are perfectly dispersed.

The mixture after the dispersion is led as shown by an arrow from thepaddy outlet 24 through a flexible conduit 25 to the cyclone separationchamber 26 as shown in FIG. 6. The cyclone separation chamber 26comprises an air outlet 27 and a hopper 28 for storing the mixture ofbrown rice, hulls, immature paddy, etc. The said mixture stored in thehopper 28 is exhausted from an opening 29 provided at the bottom of thehopper 28 and falls on a bearer plate 30 and, further, drops on a sieveplate 32 through a throwing plate 31. In that case, the good grains areaccumulated in the first deposit 33 as shown by the ordinary lines,while the immature and broken grains fall into an intermediate deposit34 as shown by the chain lines, and the residual hulls flow as shown bythe dotted lines in the air flow from an air inlet 36 caused by therevolution of a windmill 35 and discharged outside through a path 37 anda drain pipe 38. The path 37 at its upper portion may be provided withan air inlet 39 to save the amount of air flow from the air inlet 36.

The first deposit 33 is associated with a paddy throwing elevator 40which elevates and discharges brown rice through an elevating pipe 41 toa reservoir (not shown). The intermediate deposit 39 in its lowerportion is detachably provided with a truck-type container 42. When theimmature paddy and the brown rice accumulate in the container 42, theyare once again subjected to the winnower through a throwing inlet 43 tocarry out the supplemental separation.

In FIG. 7, the driving force of a prime mover 44 is transmitted to therotary shaft 10 of the hulling vanes through a pulley 45, and therevolution of the rotary shaft is further transmitted to the windmill35and the paddy elevator 40 through the pulleys 46 and 47.

According to the laboratory tests exercised by the inventor, the methodaccording to the invention could hull about 1 ton of paddy per hour byrevolving the hulling vanes at about 1,600 rpm. and the hulling yieldwas 99.9 percent. Further, it has been appreciated that even theimmature paddy, hulling of which has been regarded as impossible by theconventional rollerand collision-type huller, may be hulled perfectly bythe method and device according to the invention.

According to the present method and device, the process from the hullingto the separation of paddy is carried out by the air flow and the airpressure, and the hulling yield is extremely high, and there can be seenno crushed rice thus promoting long preservation of rice.

Moreover, the device for embodying the present method is too simple inits structure and rich in mobility, and since the operation from thesuction to the separation of paddy is all carried out automatically, thedifficult and complicated operations of the screen required in theconventional huller have all become useless.

Further, the rubber roller-type huller is not suitable for the combinedharvester thresher which is usually operated under the intensiveoscillations. On the contrary, since the device according to theinvention is not adversely affected by the oscillation and does notrequire any complicated adjustment as is usually done in theconventional huller, it is quite effective when combined into such thecombined harvester thresher.

While certain preferred embodiments of the invention have beenillustrated by way of example in the drawings and particularlydescribed, it will be understood that various modifications may be madein the methods and constructions and that the invention is no waylimited to the embodiments shown.

Iclaim:

1. A method of hulling paddy comprising the steps of placing paddy intoa housing which forms a hulling chamber; providing in said hullingchamber a plurality of radially arranged vanes with outwardly bent endsrotating said vanes so as to produce a decreased pressure zone along thevanes; passing the paddy radially outwardly along the vanes and thusthrough the lower pressure zone to thereby enable captive gas within thepaddy to expand abruptly; impacting the paddy against the bent end ofthe vane to split the hull; and discharging the husked paddy into an airpressure zone between the bent ends of the vanes and the housing.

2. A method of hulling paddy as in claim 1 wherein passing of the paddyalong the vanes is facilitated by a bend at the radially innermost endof the vane.

3. A method of hulling paddy as in claim 1 which comprises theadditional step of selecting a rate of rotation and an angle of bend forthe vane whereby the pressure at the radially outermost portion of thevane is less than the pressure at the radially innermost portion of thevane.

4. A method of hulling paddy as in claim 1 which comprises additionalsteps of removing the huskedmixture from the hulling chamber andseparatingsuch mixture into its component parts of rice and hulls.

5. A device for hulling paddy supplying means and acircular hullingchamber in which numerous hulling vanes are radially arranged aroundarotary shaft, each of said hulling vanes comprising an inner bent endfor guiding the paddy, a straight I body, and an outer bent end againstwhich the paddy impacts vane. V

1. A method of hulling paddy comprising the steps of placing paddy intoa housing which forms a hulling chamber; providing in said hullingchamber a plurality of radially arranged vanes with outwardly bent endsrotating said vanes so as to produce a decreased pressure zone along thevanes; passing the paddy radially outwardly along the vanes and thusthrough the lower pressure zone to thereby enable captive gas within thepaddy to expand abruptly; impacting the paddy against the bent end ofthe vane to split the hull; and discharging the husked paddy into an airpressure zone between the bent ends of the vanes and the housing.
 2. Amethod of hulling paddy as in claim 1 wherein passing of the paddy alongthe vanes is facilitated by a bend at the radially innermost end of thevane.
 3. A method of hulling paddy as in claim 1 which comprises theadditional step of selecting a rate of rotation and an angle of bend forthe vane whereby the pressure at the radially outermost portion of thevane is less than the pressure at the radially innermost portion of thevane.
 4. A method of hulling paddy as in claim 1 which comprisesadditional steps of removing the husked mixture from the hulling chamberand separating such mixture into its component parts of rice and hulls.5. A device for hulling paddy supplying means and a circular hullingchamber in which numerous hulling vanes are radially arranged around arotary shaft, each of said hulling vanes comprising an inner bent endfor guiding the paddy, a straight body, and an outer bent end againstwhich the paddy impacts to cause splitting of the hull of said paddy. 6.The device of claim 5 in which said inner bent has a curvature of about20* to 28*, , and the outer bent has a curvature of about 40* to 45*relative to the main body of the hulling vane.